1. Field of the Invention
The present invention relates to a coding apparatus, a coding method, a program for a coding method, and a recording medium recording a program for a coding method. The present invention is applicable to, for example, a coding apparatus conforming to the ITU (International Telecommunication Union)-T Recommendation H. 264 (hereinafter, simply referred to as H. 264). According to the present invention, a characteristic curve indicating the strength of a deblocking filter is calculated from the complexity of intra-coding and the complexity of inter-coding with the data amount per unit time taken as a variable, and the strength of the deblocking filter is calculated from this characteristic curve, thereby setting the strength of the deblocking filter automatically and appropriately.
2. Description of the Related Art
In the related art, a coding apparatus conforming to H. 264 suppresses block noise by a deblocking filter. In this regard, H. 264 defines the strength of a deblocking filter by parameters α and β. In the initial setting, the parameters α and β are set in accordance with quantization parameters. In H. 264, the On/Off of processing by a deblocking filter is set in the slice header of a bit stream that is subjected to a coding process and outputted, and the strength of the deblocking filter is set on the basis of an offset value from the initial setting value.
In the related art, in the case of a coding apparatus conforming to H. 264, a decoded image is visually observed by the operator to adjust the offset value to be set in the bit stream, thereby adjusting the strength of the deblocking filter.
A contrivance related to the above processing of the deblocking filter is proposed in Japanese Unexamined Patent Application Publication No. 2006-174138. Further, a configuration for dynamically switching a GOP structure on the basis of parameters extracted from video data is disclosed in Japanese Unexamined Patent Application Publication No. 2007-19994.
In this connection, it would be convenient if the strength of a deblocking filter can be set automatically and appropriately.